1. Field of the Invention
This invention relates to a force measuring device, more particularly to a force measuring device adapted for mounting in a bottom bracket of a bicycle.
2. Description of the Related Art
Generally, the treading force exerted by a cyclist during cycling will cause deformation of the bicycle frame, i.e., a displacement of two construction parts relative to each other. A measuring device is employed to measure such a displacement for calculating a magnitude of the force which is exerted on the bicycle by a bicycle chain. Such measurement data can be collected and subsequently analyzed and recorded. Conventional bicycle chain force measuring devices are typically mounted on a rear wheel axle since the bending occurring in the rear wheel axle is a good measure of the tension present in a bicycle chain, such as those disclosed in WO 03/073057 A1, WO 01/30643 A1, and U.S. Pat. No. 7,814,800 B2. However, the bending of the rear wheel axle which is to be measured is not truly representative of the treading force since the treading force is transmitted to the rear wheel axle from crank arms through a chainwheel and a chain.